Patent literature has disclosed many types of torches and burners, the following U.S. Pat. Nos. being noted:
65,709, June 12, 1900, granted to E. F. L. Foulger and J. G. Glover disclosed a lighting torch inside inner and outer perforated casements;
1,802,626, Apr. 28, 1931, granted to B. K. Boyd and H. Kirsch on Apr. 28, 1931, disclosed a gas-fed fire lighter with perforated end;
3,338,286, Aug. 29, 1967, granted to K. L. Hujsak and H. Crekel, W. H. Anderson and J. W. Kirkpatrick disclosed a lighter-type burner recessed in a combustion chamber;
3,723,050, Mar. 27, 1973, granted to W. C. Stevens, Jr. and P. M. More disclosed a burner with an end closure having holes and open sides;
3,729,287 granted to O. T. Strashok on Apr. 24, 1973, disclosed an ignition torch with air-induction inlet and slotted coaxial tube shields.
However, because of complexity and expense of construction and, in some cases, lack of the knock-about-durability required in heavy industrial use, not one of the above types has become a widely used standard for the industry. Most existing natural gas lighter-torches are simply hose with a length of pipe affixed on the end. The free end of the pipe is, when used to ignite a zone burner, thrust into the burner port. Because forced air for combustion and steam also flows through burner ports, torch flames of natural gas, which is of very slow propagation characteristics, are sometimes lifted off burners, torches, etc. and frequently extinguished completely. This leaves a potentially hazardous situation of raw ignited gas flowing at a high rate into the furnace.